Delay lines may be used for adjusting the timing of various signals in an electronic system. A delay line may have multiple serially connected delay elements with an input signal being delayed by each delay element. The outputs of the delay elements may be tapped to provide the input signal delayed by different amounts. The taps of the delay line may be selectable such that one of the taps is selected to provide the input signal delayed by a desired amount.
In one application, a delay line may be used to adjust a clock signal for reliably sampling a data signal. The delay line may cover the entire eye pattern of a data signal so that one of the taps may be selected to satisfy the setup and hold times for sampling the data signal. Determining which tap to use to sample the data signal may be problematic because of non-linearity of the delay line. That is, each delay element of the delay line may introduce a different amount of delay. In some systems, delay lines may be specifically designed to reduce the non-linearity. However, such delay lines tend to be expensive in terms of circuit resources.